Unpaired Floquet Majorana fermions without magnetic fields

Abstract

Quantum wires subject to the combined action of spin-orbit and Zeeman coupling in the presence of \emph{s}-wave pairing potentials (superconducting proximity effect in semiconductors or superfluidity in cold atoms) are one of the most promising systems for the developing of topological phases hosting Majorana fermions. The breaking of time-reversal symmetry is essential for the appearance of unpaired Majorana fermions. By implementing a \emph{time-dependent} spin rotation, we show that the standard magnetostatic model maps into a \emph{non-magnetic} one where the breaking of time-reversal symmetry is guaranteed by a periodical change of the spin-orbit coupling axis as a function of time. This suggests the possibility of developing the topological superconducting state of matter driven by external forces in the absence of magnetic fields and magnetic elements. From a practical viewpoint, the scheme avoids the disadvantages of conjugating magnetism and superconductivity, even though the need of a high-frequency driving of spin-orbit coupling may represent a technological challenge. We describe the basic properties of this Floquet system by showing that finite samples host unpaired Majorana fermions at their edges despite the fact that the bulk Floquet quasienergies are gapless and that the Hamiltonian at each instant of time preserves time-reversal symmetry. Remarkably, we identify the mean energy of the Floquet states as a topological indicator. We additionally show that the localized Floquet Majorana fermions are robust under local perturbations. Our results are supported by complementary numerical Floquet simulations.

18 pages, 6 figures

References in corpus (20)

• Non-Abelian Anyons and Topological Quantum Computation
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Evidence of Majorana fermions in an Al - InAs nanowire topological superconductor
• Photovoltaic Hall effect in graphene
• Topological characterization of periodically-driven quantum systems
• Introduction to topological superconductivity and Majorana fermions
• Driven quantum transport on the nanoscale
• Non-Abelian Topological Order in S-Wave Superfluids of Ultracold Fermionic Atoms
• Exploring Topological Phases With Quantum Walks
• $p_x+i{p}_y$ superfluid from s-wave interactions of fermionic cold atoms
• Multichannel Generalization of Kitaev's Majorana End States and a Practical Route to Realize Them in Thin Films
• Tuning laser-induced bandgaps in graphene
• Spin-selective Peierls transition in interacting one-dimensional conductors with spin-orbit interaction
• Optical response of graphene under intense terahertz fields
• Spin-orbit induced chirality of Andreev states in Josephson junctions
• Statistical mechanics of Floquet systems with regular and chaotic states
• Kilohertz-driven Bose-Einstein condensates in optical lattices
• Spin-orbit coupling and perpendicular Zeeman field for fermionic cold atoms: observation of the intrinsic anomalous Hall effect
• Spin and charge pumping in magnetic tunnel junctions with precessing magnetization: A nonequilibrium Green function approach

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